So far, the distributed computing community has either assumed that all the processes of a distributed system have distinct identifiers or, more rarely, that the processes are anonymous and have no identifiers. These are two extremes of the same general model: namely, n processes use l different identifiers, where 1 l n. We call this model homonymous model. To determine the power of homonymous model as well as the importance of identi ers in distributed computing, this thesis studies algorithms for solving the consensus problem, one of the most famous distributed computing problem."